ive done a couple of 1800 zetec turbos (silver top) and one 2 litre ZVH turbo, was looking into the black top as a mate had one out of a mondeo, it is different on the block about the water pump area, the black top is a better engine as it has solid lifters that dont "jack" up like the ones on the early zetecs, hence the water thin oil recomended 5w 30! not sure about the vvt head off the st 170 though are they not chain drive and totaly different? plus there will be some serious complications with the control of the vvt. I would definatly try get the correct head for your block though, should be an easy enough swap. What manifolds are you planning on using? i modified the rail in one of my zetecs to take 444cc sidefeed injectors from a subaru, this was an escort xr3i 130 alloy manifold, and welded my own exhaust manifold up out of mild steel, both of which worked well.(1.8 zetec, decomp plate, subaru turbo, 204bhp and 214lbft @12 psi)